To enable the efficient elimination or controlling of unwanted insects in agricultural and other applications, it is desirable to use effective chemical insecticides on these unwanted pests. Formulations containing multiple insecticides are desirable in order to broaden the spectrum of economically important insect, mite, and other pest species killed or controlled and take advantage of the individual pesticidal characteristics of each of the active ingredients.
Compositions containing two or more insecticides have been practiced in the art, but problems with the physical stability of such mixtures in water have caused application and efficacy issues. When traditional insecticidal compositions are combined, the combined components (surfactants, viscosity modifiers, wetting agents) of both may cause accelerated physical degradation (phase separation) of the mixture when diluted in low to moderately hard water. This physical degradation can occur in the mix tanks prior to application on plants or another locus where control is desired. Often this problem goes unnoticed and a uniform application of the insecticide mixture is not achieved, yielding inadequate efficacy.
Typically, in commercial applications, the insecticidal formulation comprises less than one percent of the tank mixture to keep the cost of the formulation low, while still yielding spectrum and onset of visual symptomology benefits. The physical stability of the formulation when diluted with water is a key problem in the art.